Fuel burning furnace



Oct. 10, 1933. H. c. HEATQN- 1,929,424

FUEL BURNING FURNACE Original Filed June 15. 1926 2 Sheets-Sheet 2 m gm INVENZOR ATTORNEKS Patented a. 10, 1933 1,929,424

UNITED STATES PATENT orrlca Application June 15, 1926, Serial No. 116,078 Renewed January 3, 1933 Claims. (01. 110-22) This invention relates to a furnace that is 20 to enter the solid fuel on the top run of the adapted for steam boilers, in which solid fuel is stoker. burned and valuable by-products are recovered A pipe 23 leads from the space between the hopfrom the fuel. The invention will be understod per 15 and wall 8 to a by-products recovery device 5 from the description in connection with the ac- 24 of any suitable type, by which valuable prod- 60 companying drawings, in which Fig. 1 is a veructs may be recovered from vapors and gases. tical section through an embodiment of the in- An outlet pipe 25 leads from the by-products vention, and Fig. 2 is a similar section on a recovery device 24 to a pump 26, from which a smaller scale showing additional features. pipe 27 leads into an inlet 28 through the com- Inthe drawings, reference character 5 indibustion arch 9 behind the wall 8.

cates the combustion chamber of a furnace that The operation is as follows: Solid fuel conis provided with a chain grate stoker 6. The taining valuable volatile constituents, such as stoker may be provided with air boxes 6' of the coal, for example, is fed through the hopper well-known type to enable regulated quantities to the upper run of the chain grate stoker 6,

15 of air to be fed through the upper run of the upon which it forms a bed which is carried into 70 stoker to the fuel, the regulation being achieved the furnace, it being understood that the upby the usual dampers, not shown. The furnace per run of the grate is moved towards the right is provided with an extension '7, over the front as shown in the drawings, this movement beend of the stoker, and a wall or baffie 8 extends ing caused by the usual sprocket wheels indifrom the combustion arch 9 of the extension cated in the drawings. The fluid fuel, such as 75 downwardly to a short distance from the upper gas, or oil, or powdered fuel fed through the run of the chain grate stoker 6, thus separating p 6 is ignited after it passes through t e the space above the grate into two compartments, holes 7 i the M058 P p air being ed in the combustion chamber 5 and a heating or igthrough the p p 0 for combustion p p niting chamber 5. A gas seal plate 8' extends and the hot products heat the solid fuel on so from the lower end of baffie 8 downwardly to the stoker, thus causing volatile products thereprevent escape of gases under the baflle 8. A from t r n p through the p p 3 into water tube steam boiler of well-known type comthe by-p e y device 24 Where the prising i lin d t be 10, a dr 11 and'bames valuable products therein are separated. The

12 may be installed above the furnace, so as to uncondensed gases from the volatile constituents 85 be heated thereby. A water tube 13 connected p ut Of the p p 25 and are forced y means to the circulatory system of the boiler may be of the p p 26 through th i et 28 into the located in the rear of the furnace near the rear combust Sp of the furnace Where t y end of the stoker 6 to cool the same and proare burned and the heat therefrom is available tect the rear wall of the furnace. for heating the boiler.

A feed inlet or hopper 15 for solid fuel is pro- The residue of the solid fuel from which volavided near the front end of the chain grate tile constituents have been removed, as just destoker, and its rear wall is provided with an adscribed, are Carried y the ain ate Stoker justable slide or gate 15' to regulate the thickness under the lower edge of the a d are of the layer of solid fuel that is fed to the stoker. burned on the up u of the c ain rate A valved pipe 16 is located in front of the hopper k the usual manner, the a $he$ and t and a cross pipe 1'? at the end thereof is provided faumg mto the ash Flt Besldes enabhng with holes on the side toward the fuel feed, this va1 uab1e 'Pm to be recovered from the pipe being connected to a fluid fuel source such solid fuel, th1s invention enables the chain grate as gas, or oil, or powdered fuel. A refractory i q to be operated at hlgtler speed and the oiler to be operated at a higher rate, as the wall 18 extends along the front of the pipe 17. f 81 is burned immediate} rte 1 tn An air supply pipe 19 terminating in a cross pipe y r W a G stituents are removed therefrom before the fuel 20 with holes 21 along its rear side is disposed on has cooled the front side of the wall 18. A casing 22 extends A Sumcient amount of is supplied through around the PIP6 and dlstance below the boxes 6' to cause combustion of the fuel inthe wall 18 and pipe 17. The front edge of the the chamber 5 and suflicient air is also supplied pp y be Slightly Spaced from the upper to the chamber 5' to permit ignition of the fuel run of the chain grate stoker 6 to enable the fuel therein. It will be noted that one of the boxes 55 leaving the pipe 17 and the air leaving the pipe 6' is placed beneath this chamber or compartno ment for the above purpose.

The result is two chambers 5 and 5' separated by the wall 8, and through these chambers is moved a bed of fuel which is ignited in the chamber 5 and then burned in the combustion chamber 5. The chamber 5' is in effect a partial combustion chamber although the amount 'of air is kept low so as to permit recovery of the volatile elements which are driven off by the heat. The fuel on the bed in the chamber 5 is therefore in such a condition that it will burn much more rapidly when it reaches the chamber 5 and therefore the stoker may be operated at a higher rate of speed. The heat from the bed in the chamber 5 will work back beneath the wall 8 and seal 8 and be conveyed through the bed to that portion of the bed in the chamber 5. After operation has continued for a time the source of fuel provided by the pipe 17 may be heat in the chamber 5 then being supplied directly from the bed. It will also be seen that the two chambers 5 and 5' are under different pressures, the different pressures being maintained by the suction through the pipe 23 and the force of the gases passing through the pipe 27, and also by regulation of the boxes 6. By this means the ignition and burning of the fuel in the two chambers may be controlled.

Various modifications or changes may be made without departing from the spirit or scope of this invention.

I claim:

1. In combination, a chain grate stoker for supporting a moving bed of fuel, means comprising a transverse wall extending above the bed of fuel for providing a front compartment and a rear compartment separated therefrom and located above said stoker, a fluid fuel bumer located immediately above the front end of said stoker for raising the temperature of the fuel in said front compartment, means for recovering volatiles liberated therein, the residue of the solid fuel being burned in said rear compartment.

2. In a furnace, a chain grate stoker, means for delivering solid fuel to the front end of said stoker, means comprising a fluid fuel burner for heating the solid fuel on the front end of said stoker, means forming two separated chambers located above the upper run of said chain grate and longitudinally thereof and followingsaid means forheating the solid fuel, means for removing ,volatile' products from the first of said chambers, means for.recovering volatile constituents from-said products, the residue from the solid fuel from the first chamber being burned in said second chamber. shut off and the operation will continue, the

4. In a furnace, a chain grate stoker, means for delivering solid fuel --.to the front end of said stoker, means comprising a fluid fuel burner for heating the solid fuel on the front end of said stoker, means-forming two separated chambers located above the upper run of said chain grate and longitudinally thereof and following said means for heating the solid fuel, means for removing the products resulting from heating the fuel from the first of said chambers, means forrecovering volatile constituents from said products and means for returning other constituents from said volatile products to the second chamber to assist in burning the solid fuel therein, the residue of the solid fuel from the first chamber being burned in the second chamber;

5. In combination, a chain grate stoker for supporting a moving bed of fuel, a wall extending transversely of said bed and dividing the space thereabove into a front and rear compartment with respect to the movement of the bed of fuel, afiuid fuel burner located immediately above the front end of the said chain grate stoker and in advance of said front compartment for heating the fuel, means associated with said front compartment for recovering constituents of the volatile products liberated in said front compartment, the residue of fuel from said compartment being burned in said rear compartment as the fuel bed moves thereinto.

HERMAN C. HEATON. 

